phavoc said:
Guerrilla ships in the outer system would, at least for Sol, be at least 100 AU out before normal drives stopped working. Let's assume an enemy jumps 200 AU into the outer system. Since there is nothing out there where is the guerrilla warfare? That label implies hiding and attacking, but it's essentially empty space, thus of no military or strategic value. Therefore there would be no fighting there.
They hide there and force you to garrison the system until they run out of supply and maintenance. Which may take years.
Unless you somehow go out there and catch them. Say by using a jump drive into empty space then chasing them down with an m-drive of some type. You probably can’t catch them anyway because it takes a week to jump, but them being there must be dealt with somehow. And maybe you can catch them, since you might work out where their fuel caches are, and then you have to fight people in deep space.
Edit: Defending deep space jump bridges as well.